The UK’s Health Protection Agency (HPA) is asking people with symptoms of norovirus infection to stay away from hospitals and care facilities so as not to put at risk those who are already ill and thus vulnerable to catching the vomiting and diarrhea virus.
“If you need advice it is best to phone NHS Direct or your doctor,” John Harris, HPA’s expert on norovirus, says in an update on seasonal norovirus activity that the independent agency released on Tuesday.
Norovirus, also called the winter vomiting bug, affects people of all ages because the virus is always changing and immunity doesn’t last. It is the most common stomach bug in the UK, where usually between 600,000 and 1 million people catch it every year.
Although more common in winter, the virus can be caught at any time of year.
The virus is highly contagious, and causes vomiting and diarrhea (sometimes with fever, headache and stomach cramps), but in most cases the illness is generally mild and people usually make a full recovery within 2 to 3 days with no lasting effects.
There is no cure, so if you catch it you have to let it run its course, and make sure you drink plenty of fluids to avoid dehydration.
Good hand hygiene helps prevent it spreading.
The virus spreads by contact with contaminated surfaces or objects. You can also catch it from touching an infected person, or by consuming contaminated food or water.
In an effort to find out how far the extremely contagious germs travel when a person with the sickness throws up, researchers from the UK Health and Safety Labs have invented a vomiting robot called “Larry”.
Figures Higher for this Time of Year
The HPA reports that the latest norovirus infection figures for this time of year are higher than they were at the same time last year.
So far this season, the number of lab-confirmed cases is 4,407, which is 56% higher than they were for the same period last year when there were 2,828 lab-confirmed cases.
The HPA estimates that for every case that is confirmed, there are another 288 unreported, as the vast majority of those affected do not go to their doctor or seek help from a health service.
This puts the estimated number of infections so far this year at over 1.25 million.
A new strain of norovirus, called Sydney 2012, has been circulating in the UK this season. Although HPA surveillance detected the strain at the start of the season. At that point it was not the dominant strain, but recent testing shows it now is. This could be a reason for the early start to the season, says the agency.
Upredictable Patterns of Virus Activity
The HPA’s latest update shows the downward trend in confirmed cases that started in December is continuing, with a 32% drop in cases between the last week of December and the first week of January (257 lab-confirmed cases down to 175).
There has also been a drop in hospital outbreaks: with 39 outbreaks reported in the two weeks up to 13 January, compared with 33 in the previous fortnight. The total number of hospital outbreaks so far this seasion is 728.
The agency says this pattern shows the “unpredictability of the norovirus season where the number of confirmed cases rises and falls”, and warns that they still expect to see new cases arising before the season ends.
“Norovirus activity always varies from year to year and although we might have expected cases to rise again now we have passed the New Year period this hasn’t been the case.”
But he warns that this drop doesn’t necessarily mean anything, so we can’t tell how busy the rest of the season will be.
“The busiest months are normally from December to April, so further cases will occur but we can’t say if there will be further significant increases in the number of laboratory reports,” says Harris.
Written by Catharine Paddock PhD
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